The SNARE Complex from Yeast Is Partially Unstructured on the Membrane

jerry submitted, created time 4 months 6 days (www.structure.org)

Molecular recognition between cognate SNAREs leads to the formation of a four-helix bundle, which facilitates vesicle docking and membrane fusion. For a SNARE system involved in trafficking in yeast, target membrane (t-) SNARE Sso1p and vesicle associated (v-) SNARE Snc2p contribute one SNARE motif each, whereas another t-SNARE (Sec9) donates two N-terminal and C-terminal SNARE motifs (SN1 and SN2) to the helical bundle. By use of EPR, it is found that SN2 has a tendency to be uncoiled, leaving a significant population of the SNARE complexes to be partially unstructured on the membrane

2 comments | Blog It | Email It | Keywords: Sso1p Snc2p Sec9 membranes vesicle docking SNARE membrane fusion SN2 SNARE protein

The Transport Signal on Sec22 for Packaging into COPII-Coated Vesicles Is a Conformational Epitope

badboy submitted, created time 1 year 6 months (www.molecule.org)

"The mechanism of cargo concentration into ER-derived vesicles involves interactions between the COPII vesicular coat complex and cargo transport signals—peptide sequences of 10–15 residues. The SNARE protein Sec22 contains a signal that binds the COPII subcomplex Sec23/24 and specifies its endoplasmic reticulum (ER) exit as an unassembled SNARE. The 200 kDa crystal structure of Sec22 bound to Sec23/24 reveals that the transport signal is a folded epitope rather than a conventional short peptide sequence

Submit comment | Blog It | Email It | Keywords: Sec22 SNARE protein endoplasmic reticulum